CVE-2026-12802: Bouncycastle Bc-Java

High severity, CVSS 7.5. EPSS: 0.1% chance of exploitation in the next 30 days.

In Bouncy Castle for Java before 1.85, CMS AuthEnvelopedData fails to enforce tag-length on decryption. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series).

Affected products

• Bouncycastle Bc-Java: before 1.85 (fixed in 1.85)
• Bouncycastle Bcpkix-Fips: before 1.0.12 (fixed in 1.0.12); from 2.0.7, before 2.0.12 (fixed in 2.0.12); from 2.1.8, before 2.1.12 (fixed in 2.1.12)
• Bouncycastle Bouncy Castle For Java LTS: up to and including 2.73.11

Published 2026-08-03. Last modified 2026-09-02.